Use utils.forEach everywhere rather than Array.prototype.forEach to guard

chrome/renderer/resources/extensions/utils.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 var chrome = requireNative('chrome').GetChrome();
 
-function forEach(dict, f) {
-  for (var key in dict) {
-    if (dict.hasOwnProperty(key))
-      f(key, dict[key]);
+function forEach(obj, f, self) {
+  // For arrays, make sure the indices are numbers not strings - and in that
+  // case this method can be more efficient by assuming the array isn't sparse.
+  //
+  // Note: not (instanceof Array) because the array might come from a different
+  // context than our own.
+  if (obj.constructor && obj.constructor.name == 'Array') {
+    for (var i = 0; i < obj.length; i++)
+      f.call(self, i, obj[i]);
+  } else {
+    for (var key in obj) {
+      if (obj.hasOwnProperty(key))
+        f.call(self, key, obj[key]);
+    }
   }
 }
 
 // Assuming |array_of_dictionaries| is structured like this:
 // [{id: 1, ... }, {id: 2, ...}, ...], you can use
 // lookup(array_of_dictionaries, 'id', 2) to get the dictionary with id == 2.
 function lookup(array_of_dictionaries, field, value) {
   var filter = function (dict) {return dict[field] == value;};
   var matches = array_of_dictionaries.filter(filter);
   if (matches.length == 0) {
@@ skipping 12 matching lines @@
   var parts = ref.split(".");
   if (parts.length > 1)
     return chrome[parts.slice(0, parts.length - 1).join(".")];
   else
     return currentApi;
 }
 
 exports.forEach = forEach;
 exports.loadRefDependency = loadRefDependency;
 exports.lookup = lookup;